I would like to see more integration to LinkedIn, but I'm not sure if SO Careers has too many crossovers; like uploading CVs and job adverts for example. But as SO will never be a social network linking to the best career building social network would benefit both SO and LinkedIn.
I would be more than impressed if SO spoke to LinkedIn and got LinkedIn to allow SO flair to be added as a Linked In application - in the same way that your Amazon Reading List, GitHub projects, Tweets, some blog types and so on can be added to your LinkedIn profile.
I think SO flair as a LinkedIn application will guide many more people from LinkedIn to SO as it would not put off non-technical people - and it would enhance the implicit value of the SO reputation.